US 11,938,913 B2
Power brake system of a vehicle and method for controlling same
Michael Haverkamp, Hannover (DE); and Lars Volker, Seelze (DE)
Assigned to ZF CV Systems Global GmbH, Bern (CH)
Filed by ZF CV Systems Global GmbH, Bern (CH)
Filed on Sep. 30, 2021, as Appl. No. 17/449,461.
Claims priority of application No. 10 2020 125 639.6 (DE), filed on Oct. 1, 2020.
Prior Publication US 2022/0105911 A1, Apr. 7, 2022
Int. Cl. B60T 8/1755 (2006.01); B60T 8/36 (2006.01); B60T 13/22 (2006.01); B60T 13/68 (2006.01)
CPC B60T 8/17551 (2013.01) [B60T 8/361 (2013.01); B60T 13/22 (2013.01); B60T 13/686 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A power brake system (1.1, 1.2, 1.3, 1.4) of a vehicle (2), comprising:
a pressure medium source (14),
a pressure-medium-operated primary brake system (30), which can be used as a service brake and steering brake system, the primary brake system (30) including at least one foot brake valve (36a, 36b) and at least two wheel brake cylinders (40a, 40b) arranged on opposite sides on a drive axle (8) and configured to be actuated independently of one another,
a pressure-medium-operated secondary brake system (50; 50′; 68; 100) operable independently of the primary brake system (30) and configured to be used at least as an auxiliary brake system, the secondary brake system (50; 50′; 68; 100) including a brake control valve (56; 70; 102) and at least one brake cylinder (62a, 62b; 62a′, 62b′; 82a, 82b), acting on wheel brakes of a vehicle axle (4, 8),
wherein the secondary brake system (50; 50′; 68; 100) is electronically controllable and includes:
the brake control valve (56; 70; 102) configured as a solenoid valve for setting a braking force of by feeding or removing pressure medium to or from the at least one brake cylinder (62a, 62b; 62a′, 62b′; 82a, 82b),
a pressure sensor (64; 90) connected to a working line (60; 60′; 74, 80) leading to the at least one brake cylinder (62a, 62b; 62a′, 62b′; 82a, 82b), and
an electronic brake control unit (46) for evaluating a pressure signal of the pressure sensor (64; 90) and for controlling the brake control valve (56; 70; 102) in accordance with a braking value signal (SBW);
wherein the brake control unit (46) is assigned a non-volatile data memory (78), storing characteristic curves (A, B, C; D, E, F), for different operating modes, for setting a working pressure (pB, pFSB) in the at least one brake cylinder (62a, 62b; 62a′, 62b′; 82a, 82b) in accordance with the braking value signal (SBW) or for calculating further characteristic curves (A′, B′, C′; D′, E′, F′);
wherein the characteristic curves are stored and correspond to different operating modes and/or vehicle types, wherein the working pressure is set as a function of the braking value signal according to a specific one of the stored characteristic curves that corresponds to the operating mode and/or the vehicle type.